Hemostasis and Coagulation

This set of flashcards covers the key topics related to hemostasis and coagulation, including blood components, processes of primary and secondary hemostasis, and the role of various factors and molecules involved.

What are the main components of blood plasma?

Water, proteins, antibodies, lipids, carbohydrates, electrolytes, clotting factors, enzymes, vitamins, hormones.

What percentage of total blood volume does plasma constitute?

55% of total blood volume.

What is the function of Primary Hemostasis?

It is characterized by the formation of a hemostatic platelet plug.

What is the difference between serum and plasma?

Serum is obtained from coagulated blood and lacks fibrinogen, while plasma is from anticoagulated blood and contains fibrinogen.

What initiates the secondary hemostasis process?

Activation of the coagulation cascade.

What role does thromboxane A2 play in hemostasis?

Thromboxane A2 promotes platelet aggregation and vasoconstriction.

What is the main structural protein in a fibrin clot?

Fibrinogen is hydrolyzed by thrombin to form fibrin.

Which factors participate in the contact system to activate coagulation?

Factors XII, XI, IX, and VIII.

What is the role of tissue factor (TF) in coagulation?

TF activates factor VII, initiating the extrinsic pathway of coagulation.

What does the coagulation cascade produce upon activation?

A thrombus, or blood clot.

What are the functions of antithrombin?

Antithrombin inactivates thrombin and other serine proteases involved in coagulation.

What factors are produced in the liver and are vitamin K dependent?

Factors II (Prothrombin), VII, IX, and X.

What is fibrinolysis?

Fibrinolysis is the process of breaking down fibrin in blood clots.

How does tissue plasminogen activator (TPA) function in fibrinolysis?

TPA converts plasminogen to plasmin, which digests fibrin.

What is the expected laboratory finding in primary fibrinolysis?

Increased D-dimer and fibrin degradation products.

What is the purpose of platelet aggregation?

To form a platelet plug during primary hemostasis.

What happens to fibrinogen during the formation of a fibrin clot?

Fibrinogen is cleaved by thrombin to form fibrin.

What are the three phases of hemolysis?

Primary hemostasis, secondary hemostasis, and fibrinolysis.

What key substances do intact endothelial cells secrete to prevent clotting?

Prostacyclin, nitric oxide, and tissue factor pathway inhibitor (TFPI).

What is the role of von Willebrand factor (vWF) in hemostasis?

vWF mediates platelet adhesion to the exposed collagen at injury sites.